Exemplary embodiments pertain to the art of environment control systems and, in particular, to an aircraft environmental control system (ECS) split pack with two bleed/outflow heat exchangers.
In general, contemporary air conditioning systems are supplied a pressure at cruise that is approximately 30 psig to 35 psig. The trend in the aerospace industry today is towards systems with higher efficiency. One approach to improve airplane efficiency is to eliminate the bleed air entirely and use electrical power to compress outside air. A second approach is to use lower engine pressure. The third approach is to use the energy in the cabin outflow air to compress outside air and bring it into the cabin. Unfortunately, each of these approaches alone provides limited efficiency with respect to engine fuel burn. An approach using bleed and cabin outflow air to power a split integrated refrigeration package, offering the operational redundancy of a typical two-pack ECS is described herein.